However, you'll probably still need a passport to get back in the U.S. With a new law called the Western Hemisphere Travel Initiative, it's no longer enough just to show a driver's license or birth certificate at the border.

If you're returning to the U.S. by air, you'll need to present a passport or other special document. Starting June 1, the same rule will apply to re-entry by land or sea as well. See www.getyouhome.gov for details.

Non-U.S. Citizens

All visitors to Canada must have a valid travel document, such as a passport.

But a passport or similar document isn't enough for some visitors. Canada requires visitors from some countries to apply for a temporary resident visa as well.